img{position: fixed;top:50%;left:50%;width:4rem;z-index: -1;margin-top: -2rem;margin-left: -2rem;}
.user-knowTitle{text-align:center;font-size: 0.36rem;line-height:1rem;}

.user-knowList{padding:0 0.3rem;font-size:0.26rem;line-height:0.46rem;text-indent:0.52rem;}
